1. Field of the Invention
The present invention relates to a storage control device and a method for extending a RAID group.
2. Description of the Related Art
A storage control device controls a RAID (Redundant Array of Independent Disks) group made up of a plurality of disk drives to generate a RAID organization such as RAID0-6 using a physical storage area provided for each disk drive. One or more logical volumes can be generated in a virtualized physical storage area provided for the RAID group. A logical volume (LU: Logical Unit) is provided for a host computer (hereinafter a host) to store the user data.
The user often decides the storage capacity of the RAID group by estimating the prospective available amount of storage to a certain extent. However, since the amount of data to be managed greatly increases in recent years, it is not uncommon that the storage capacity beyond the first predictive value of the user is required.
As a countermeasure against the insufficient storage capacity of the RAID group, a method for adding a new drive disk to the RAID group, and re-striping all the disk drives including the new disk drive is well known.    Patent document 1: JP-A-2007-323251    Patent document 2: JP-A-2007-323252    Patent document 3: JP-A-2008-003857